Maytag SE1000 discontinued thermister temperature sensor

[tabasco]

Model Number: SE1000
Brand: Maytag
Age: More than 10 years

My dryer will not heat. The thermister temperature sensor tests as open. All parts stores online and eBay say it is discontinued and none can be found. Could I use the Whirlpool 31001716 which looks very similar? Could I bypass the thermister? Any suggestions?

[denman]

Could I bypass the thermister?
No, you cannot bypass the thermistor as that is what is regulating your heat.

How did you check it for open?
You would have to have used the 200K or higher resistance scale on your meter (see below)
Just using the meter in continuity is no good because you do not know at what resistance the meter decides that there is no continuity.

I get conflicting specs for the thermistor depending where I look.
Seems the most likely correct specs are about 100,000 ohms at room temperature with it at 18,000 ohms at 140 degrees F. (re: negative temperature coefficient)
The alternate part you give would not work because it looks like it is 10,000 ohms at room temperature.

Sorry I could not be more helpful.

[tabasco]

Thanks for your reply and good information. I rechecked at the 200k setting and it tests fine! My bad.

The cycling thermostat tests closed at room temperature, so that shouldn't be the problem. The heater coil tests fine (coil shows some resistance and there is no short to ground.)

The high limit thermostat also tests with continuity.

The only other things I can think of are the heater relay and control board. How would I test the relay? (I assume test for low resistance across the coil wires and open at the heater coil terminals?) If its the control board, it's not worth the cost to replace a $230 part.

Thanks for all your help.

Ed

[denman]

I am assuming that you have already checked for 240 volts at the terminal strip in the unit.
If not that is the first thing I would do.
Just checking for the two 120 volts is not good enough as you cannot tell whether you are measuring L1 or L2 so to be sure you have 240 volts you must measure it.

There are a couple ways to check the relay.

The wiring diagram I have shows a yellow/black and a black wire on the input side of the relay contacts and a brown wire on the output.
I do not know what this connector is so you may have to remove the wires and short/tape them together or use a piece of wire/paper clip to short between them.
Just make sure your short cannot short to anything else.
Then plug the unit in and give it a try.
If you have heat then you know the relay or the electronics are the problem.
Only let it run a very short time for the test as the wires may overheat where you shorted them together.
If you still do not have heat, there is a problem in another part of the heater circuit re: centrifugal switch etc.

Another way would be to disconnect L2 from the terminal strip. This is usually a red wire but my wiring diagram shows it as blue.
Tape it or whatever to be ensure it cannot short to anything else.
Plug the unit in.
Use the frame or Neutral as the reference side of the meter.
You should see 120 volts at the yellow/black and black wires (input)
You should see 0 volts at the brown (output)
Now start the dryer.
Now you should see 120 volts at the brown.
L2 has to be disconnected so that you do not actually measure it at the brown which can get very confusing.

Also there is one other component that can cause your problem and that is the centrifugal switch on the motor.
It switches in L2 to the heater when the motor gets to operating speed.

[tabasco]

I followed your instructions and:
1) I do have 240 at the terminal
2) I unplugged the dryer, shorted the black and brown wires on the relay output, plugged in, started the dryer and immediately had heat. Yay!
3) I unplugged the dryer and relay input terminals, which my service manual says should read 490 ohms, but it reads 'open' on every scale.
4) I checked the relay input wires with the dryer running and it reads 24 volts DC, as it should.

This leads me to conclude that the relay is bad. Would you agree?

[denman]

Yes I would come to the same conclusion that you did.

If you can get some numbers off the relay you may be able to find one on the net and just replace it.

[tabasco]

Just ordered. Hopefully will arrive Friday. Thanks again for your help.

[F David Rudnick]

Honestly, keep an eye on e-Bay. Parts come up. Also, call a local handyman or repair tech. They'll know places that you will not that may have it. You'll want to keep those classic washer and dryer units... ask any Samsung or LG owner!